hi dev
while working on some performance measurements in Ignite 2 and Ignite 3 it looks like that I potentially found some regression in 2.18.0 version versus 2.17.0. It's about serialization of java.util.TreeMap and java.util.TreeSet (I didn' t check another collection though). To save the time for writing a reproducer I used AI (claude code) to I'm attaching it here. Please, read README.md in the archive for low-level details - it has quite extensive information how to run it, possible issue description and a proposed solution. After some research, it might be connected to the IGNITE-26061 (commit 06a557b2e4) but I'm not very sure at the end... Could somebody please review it (such as I don't have any deep experience with Ignite's internals) that all is true and probably assist here what would be a next step in a resolution of the issue? Many thanks in advance! Best regards, I.P.
<<attachment: g27-reproducer.zip>>
